1. In the laboratory a \"coffee cup\" calorimeter, or constant pressure calorime
ID: 1044836 • Letter: 1
Question
1. In the laboratory a "coffee cup" calorimeter, or constant pressure calorimeter, is frequently used to determine the specific heat of a solid, or to measure the energy of a solution phase reaction. A student heats 65.21 grams of nickel to 97.63 °C and then drops it into a cup containing 78.98 grams of water at 20.92 °C. She measures the final temperature to be 26.88 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.56 J/°C. Assuming that no heat is lost to the surroundings calculate the specific heat of nickel. Specific Heat (Ni) =? J/g°C.
2. In the laboratory a "coffee cup" calorimeter, or constant pressure calorimeter, is frequently used to determine the specific heat of a solid, or to measure the energy of a solution phase reaction. Since the cup itself can absorb energy, a separate experiment is needed to determine the heat capacity of the calorimeter. This is known as calibrating the calorimeter and the value determined is called the calorimeter constant. One way to do this is to use a common metal of known heat capacity. In the laboratory a student heats 90.04 grams of zinc to 99.33 °C and then drops it into a cup containing 82.06 grams of water at 21.07 °C. She measures the final temperature to be 28.26 °C. Using the accepted value for the specific heat of zinc (See the References tool), calculate the calorimeter constant. Calorimeter Constant = ? J/°C.
Explanation / Answer
1.
heat lost by metal = heat gained by water
m*s*DT = m*s*DT + c*DT
65.21*S*(97.63-26.88) = 78.98*4.18*(26.88-20.92) + 1.56*(26.88-20.92)
s = specific heat of metal(Ni) = 0.428 j/g.c
2.
heat lost by metal = heat gained by water
m*s*DT = m*s*DT + c*DT
90.04*0.39*(99.33-28.26) = 82.06*4.18*(28.26-21.07) + C*(28.26-21.07)
c = Calorimeter Constant = 4.09 j/c
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